Bottom lock for cartons



J. VESAK BOTTOM LOCK FOR CARTONS Oct. 22, 1963 v 2 sheets-Skeet" 2 Filed -June 5, 1961 EJE'.

United States Patent O 3,107,840 BG'ITii/I LUCK FR CAR'INS .Ioseph Vesar, Richmond, British Coiumhia, Canada,

assigner to Crown Zellelhach Canada Limited, Janeouver, iritish Columbia, Canaria, a corperatien ei Canada Filed .time 5, 1961, Ser. No. 114,8@1 Ciaims priority, application Canada Jane 6, 1960 4 Elanna. (Ct. 239-45) This invention relates to locks for temporarily holding the aps of the bottoms of cartons in the closed posit-ion.

Although this invention may be used with any type of carton having bottom flaps, it is particularly for cartons having top and bottom i'laps that are glued orrotherwise secured in closed positions after the carton has been loaded with bottles or the like. 'Ihis loading usually takes place in specially designed machines. These cartons are delivered to the users in collapsed or iiattened condition. During the loading operation prior to this invention, each carton was opened up and the bottom flaps folded into their normal closed positions. The carton was placed on its bottom on a conveyor for delivery to the loading machine. After the carton was loaded, it was moved out of the loading machine, and the bottom flaps were opened up by a standard plow, a wellknown type of equipment in this industry. After glue was applied to the top and bottom ilaps, these iiaps were folded inwardly and pressed into their iinal closed positions.

The idiiiculty in the past has been that after the bottom aps had been moved -into closed position the rst time and the carton placed on the conveyor, the bottom aps had a tendency to spring out of position, resulting in many cartons falling over or being tipped out of the correct position for loading.

The main purpose of the present invention is to overcome the above diiiiculty in a simple and eicient manner. 'Ihis is accomplished in such a simple way that the person who folds the bottom flaps inwardly automatically locks these ilaps in position with very little more than normal effort and without any loss of time.

'Ille cartons to which this invention is applied have inner and outer bottom flaps connected to the carton side walls and foldable inwardly into partial overlapping relationship. A bottom lock according to the present invention for this type of carton comprises a slot in the inner flap adjacent the inner edge thereof. This slot forms flap sections that are displaceable relative to each other out of the general plane of the flap. When the outer bottom iiap is folded over the inner ilap, the two flaps are simultaneously pressed inwardly of the carton beyond the normal positions assumed by said flaps when closing the carton bottom. The slot in the inner iiap is so arranged that this inward movement of the flap either results in relative ldisplacement of the flap sections or enables the operator to displace one tiap section relative to another, and when the iiaps are released, the inner edge of the outer bottom flap moves between the displaced flap sections to lock the inner and outer flaps together. In other words, in order to lock the iiaps together, the action substantially is to press them 3,137,840' Patented Oct. 22, 1961i inwardly of the carton a little beyond their normal positions, and then to release them. During this action, the flap sections are displaced relative to each other so that the inner edge of the outer ap may move between these sections where it is trapped.

Examples of this invention are illustrated in the accompanying drawings, in which, y

FIGURE 1 is a perspective view of the bottom portion of a carton with the aps thereof in the open position, and illustrating a preferred form of the invention,

FIGURE 2 is a bottom plan view of the carton with the inner flap folded into its normal closing position,

FIGURE 3 is a bottom plan view with the outer bottom flap folded into its normal closing position,

FIGURE 4 is a similar view showing the bottom aps pressed inwardly of the carton just before they are released,

FIGURE 5 is a similar view showing the bottom flaps after they have been released and locked in the closed position,

FIGURE 6 is an enlarged section takenvon the line 6--6 of FIGURE 4,

FIGURE 7 is an enlarged sect-ion taken on the line '7 7 of FIGURE 5,

FIGURE 8 diagrammatically illustrates a carton with its bottom aps locked closed approaching a plow,

FIGURE 9 is a view similar to FIGURE 1, illustrating an alternative form of the invention,

FIGURE 101is a bottom plan View of the carton of FIGURE 9 with the flaps -in the closed and locked position,

FIGURE 11 is a view similar to FIGURE 9, illustrating a variation of the carton of the latter figure, and

FIGURE 12 is a bottom plan view of the carton of `FIGURE l1 with the bottom aps closed.

Referring to FIGURES l to 7 of the-drawings, l10 is a standard carton having side walls 11` and 12, and lend Walls 13 and 14. End iiaps 1-7 and 18 are usually integrally connected with end walls 13 and 114, respectively, and are foldable inwardly thereof. Inner and outer bottom ilaps 22 and 23` are integrally connected to side walls `11 and `12? and are foldable inwardly there- -from. When carton 10 is closed, end flaps 17 and 1S are rst folded inwardly, then flap 22 is lfolded over the end flaps, after which ilap 23 is folded over and par tially overlaps flap 22. 'Ihese flaps are glued or otherwise secured together in the well-known manner.

The bottom lock of FIGURES l to 7 comprises a slot 31) in inner flap 22 adjacent the inner edge 31 thereof and preferably aboutA midway between the ends of the flap. The illustrated slot 30 is substantially Y-shaped `so that it has a substantially V-shaped upper part 33, and a straight lower part 34 extending away from the apex of the V. It is preferable that the bottom part 34 of the Y extends to and opens out through the inner edge 31 of the inner flap. This provides the best results, although the entire Y-shaped slot may be shifted inwardly a little from the iiap edge 31. In addition to this, the lock can be worked if only the V-shaped upper part 33 of the slot is lused. The apex of the slot always extends towards the inner edge 31 of the flap, and it may even extend to said inner edge.

The V-'shaped upper part 33 or slot 30 forms a substantially tl-shaped ilap section 37, while the bottom part 34 of the slot forms on the opposite sides thereof flap sections 38 and 39 which are displaceable relative to each other and to the V-shaped `ap section 37.

`j`When it is desired to place carton hit on the bottom thereof on a conveyor or other support prior to the load-ing of the carton, end flaps 17 and l are folded inwardly, and inner bottom nap y22 folded over them, as shown in FIGURE 2. Then outer bottom lflap 23 is folded inwardly over flap 22 in the usual manner, at which time it partially overlaps the latter flap, as shown in FIGURE 3. In order to lock the bottom flaps closed, it is only necessary to press said flaps near the centres of the inner edges thereof inwardly beyond the general pla-ne of said flaps, said plane being indicated by line 42 in FIGURE `6. It will be noted that at this time the inner edge of outer bottom ap 23 presses against the portion of inner flap 22 extend-ing along the inner edge 3,1 thereof. This takes place midway between the ends of the iiaps. As the ends of the -ilaps are bearing against end tllaps 17 and I8, `said endstend to stay in the normal plane of the bottom ilaps. As a result of this, when pressure is applied to the outer flap near the centre thereof, ap sections 38 and 39 which are weakened by the lower part 3d of slot 3d, move inwardly relative to diap section 37, as clearly illustrated in FIG- URE 6. When the pressure against the flaps is released, they tend to swing back to their positions generally in the planeindicated by line 42. At this time, the inner edge 44 of outer iiap 23 tends to swing through the arc indicated by line 45 in FIGURE 6. This causes edge 44 to move beneath flap section 37 where it remains when the flaps return to their normal closed position, as shown in FIGURE 5. Thus, the inner edge 44 of the outer Iiiap lis trapped between Hap section 37 and diap sections 3S and 39 of the inner iiap. This retains the bottom tlaps in a general horizontal plane so that carton lil will sit properly on the bottom vflaps, without tilting or falling over.

After carton 10 is lled in the usual manner, it is shifted towards a plow 4S which moves into opening 46 between end iiap I7 or 18 and the bottom naps Z2 and 23. The plow is shaped to swing the bottom flaps outwardly relative to the sidewalls of the carton so that glue may be applied thereto. At the 4same time, glue is applied to the top flaps of the carton in accordance with standard practice, after which the top and bottom flaps are -folded inwardly to close and seal the top and bottom of the carton.A This operation is standard practice and -does not require any special description herein.

FIGURES 9 and l0 illustrate an alternative form of bottom lock incorporated in a carton 55 having `bottom endk ilaps 56 and 57, and inner side bottom flap 53, and an outer side bottom flap 59. The lock in this form of the invention comprises a slot '62 in outer flap 53 preferably about midway between the ends thereof and extending to and opening out through the inner edge 65 of the iiap. This slot forms -ap sections 67 and 68 on opposite sides thereof which are relatively displaceable.

In order to lock the bottom flaps of carton 55 in the closed position, end iiaps 56 and 57 are iirst folded inwardly, after which inner and outer bottomiiaps 5S and 59 are consecutivelyyfolded inwardly into partial overlapping relationship. Then outer ilap 59 is pressed inwardly near the inner edge V6h thereof to move both bottom flaps inwardly of the carton beyond their norrnalfpositions. The inward ymovement of the outer flap is continued unt-il the edge 60 of the outer ilap moves inwardly past the edge 65 of the inner iiap. At this time, the operator depresses either oi the flap sections 67 or 68, `for example, section 67, and the-n the pressure Y on the diaps is released. As the outer ilap swings back to its normal position, it swings beneath ilap section d8 and over ilap section 67 so that the outer flap is trapped between said flap sections. This results in the inner and outer bottom ilaps being locked together substantially in the general plane of the ilaps when they are in their normal closed position. From here on, the

carton is treated in the same manner as carton 2li)l described above.

If the bottom part 3d of slot 30 of carton l0 is omitted, I

the locking operation is the same as above, excepting that the operator may have manually to displace ap section 37 outwardly of inner ap 22 in order to be sure that the edge 44 of outer flap 23 moves beneath said flap section when the pressure on the bottom :aps is released.

FIGURES ll and l2 illustrate a variation of the bottom lock of FIGURES 9 and l0. Side bottom flaps 58d and `59a of carton 55a. are a little wider than aps 5S and 59 of carton 55. Flap 53a has slot 62a. therein, while ilap 59m has a corresponding slot 'I2 about midway between the ends thereof and opening out through its inner edge '73. The latter slot forms flap sections 75 and '76 on opposite sides thereof.

When flaps 58a and 59a are swung inwardly, the operator depresses a iiap section of each relative to other liap section of its flap. For example, ap sections 67a and a are depressed, and the inner edges of the flaps i are manipulated so that ilap sections 68m and 76 over- FIGURES l to 7, the actual locking takes place autoi Y matically when the operator releases the inwardly-pressed bottom -flaps. With the alternative of FIGURES 9` and l0, he merely has to depress one of the iiap sections 67 or 68 after he has pressed the bottom flap inwardly. Once this is done, the locking takes place automatically upon release of the bottom aps. In both cases, the natural tendency of the bottom faps to swing baok and outwardly relative to the carton, causes the flaps to lock together. This lock, however, is such that it is very easy to force the bottom aps outwardly 4relative to the carton in order to release the lock.

What I claim as my invention is:

1. An end closure lock for cartons having side walls, comprising inner and outer flaps connected to opposite carton walls, said flaps being of a size to overlap a little at inner edges thereof when folded inwardly relative to the carton, a substantially Y-shaped slot in the inner ilap with the part of the slot forming the bottom of the Y extending to and opening out through the inner edge of the inner iiap, the upper part of the Y slot forming a substantially V-shaped iirst ilap section and the bottom part of the Y forming on opposite sides thereof second and third ap sections that are displaceable relative to each other and to the iirst flap section, whereby when the outer hap fis pressed inwardly over the-inner ap beyond the normal positions of said flaps, the second and third iiap sections move Yrelative to each other.

and are depressed relative to the iirst ap section, and when the outer ap is released the inner edge thereof moves over the second and third flap sections and beneath the irst flap section releasably to lock the inner and outer flaps together.

2. An end closure lock for cartons having side walls, .comprising inner and outer flaps connected to opposite side walls, each of said aps being free from tabular projections on their `inner ed-ges, said iiaps foldable inwardlyand being of a size to overlap at their inner edges such that when folded inwardly one flap is an inner flap and the other is an outer ilap, a slot -in the inner ap forming a first ap section having an edge freed from the remainder of the inner flap, said rst ap section extending towards the inner edge of said inner flap, and a slit in the inner flap extending from the inner edge thereof to a point intermediate the ends of the slot in said inner iiap, said slit forming second and third ap sections being movable downwardly relative to the first :Hap section and away from each other, vwhereby when 10 the outer ilap is pressed inwardly over the inner flap beyond the normal positions of said ilaps, the second and third ap sections move away from each other and are depressed relative to the rst flap section, and when the outer ilap is released the inner edge thereof moves 15 3,043,711

5 forming the first ap section is V-shaped.

4. A lock as claimed in claim 3 wherein the slit extends to the apex of the V-shaped slot.

References Cited in the file of this patent UNITED STATES PATENTS 513,760 :Clark Jan. 30, 1894 2,596,087 Shoudy May 6, 1952 2,612,307 Waggoner Sept. 30, 1952 2,987,973 Chandler June 13, 196-1 Kronson et al. Dec. 19, 1961 

1. AN END CLOSURE LOCK FOR CARTONS HAVING SIDE WALLS, COMPRISING INNER AND OUTER FLAPS CONNECTED TO OPPOSITE CARTON WALLS, SAID FLAPS BEING OF A SIZE TO OVERLAP A LITTLE AT INNER EDGES THEREOF WHEN FOLED INWARDLY RELATIVE TO THE CARTON, A SUBSTANTIALLY Y-SHAPED SLOT IN THE INNER FLAP WITH THE PART OF THE SLOT FORMING THE BOTTOM OF THE Y EXTENDING TO AND OPENING OUT THROUGH THE INNER EDGE OF THE INNER FLAP, THE UPPER PART OF THE Y SLOT FORMUNG A SUBSTANTIALLY V-SHAPED FIRST FLAP SECTION AND THE BOTTOM PART OF THE Y FORMING ON OPPOSITE SIDES THEREOF SECOND AND THIRD FLAP SECTIONS THAT ARE DISPLACEABLE RELATIVE TO EACH OTHER AND TO THE FIRST FLAP SECTION, WHEREBY WHEN THE OUTER FLAP IS PRESSED INWARDLY OVER THE INNER FLAP BEYOND THE NORMAL POSITIONS OF SAID FLAPS, THE SECOND AND THIRD FLAP SECTIONS MORE RELATIVE TO EACH OTHER ND AND ARE DEPRESSED RELATIVE TO THE FIRST FLAP SECTION, AND WHEN THE OUTER FLAP IS RELEASED THE INNER EDGE THEREOF MOVES OVER THE SECOND AND THIRD FLAP SECTIONS AND BENEATH THE FIRST FLAP SECTION RELEASABLY TO LOCK THE INNER AND OUTER FLAPS TOGETHER. 